Ignition system problems, check the working conditions of spark plugs, high-voltage lines and ignition coils. Poor ignition system and poor spark plug misfire can also lead to such failures.
The oil pressure is unstable. If the oil supply pressure of the oil pump is abnormal, or the intake pressure sensor has an incorrect value and works poorly, it will lead to the body shaking.
Engine parts are aging, and the engine foot is actually the shock absorption system of the engine. The engine foot is responsible for absorbing slight vibration when the engine is running. If there is something wrong with the engine foot, these vibrations will be transmitted to the steering wheel and cab, causing idling jitter.
I hope it helps you.